The key takeaways from this video is that in May 2010, Google did not use any social signals in their algorithms. Today they do. Matt explained it is mostly used in the real-time search index but they are “studying” how they may expand it more into other areas of search, including web search.

Matt warns that you should not just go out and get tons of followers, it won’t help you rank well. What will is getting followers that have good reputation. What makes a follower have good reputation? He did not say, but I would assume a mix of the number of his followers, the number of retweets, the links in his tweets, how reputable his followers are and so on.